High mobility titanium-doped indium oxide for use in tandem solar cells deposited via pulsed DC magnetron sputtering

© 2014 The Authors. The effects of pulsed DC (PDC) magnetron sputtering on the crystalline structure of the high mobility transparent conducting oxide (TCO), titanium-doped indium oxide (ITiO), are investigated. High mobility (μ >100 V-1s-1cm2) ITiO films are deposited by PDC magnetron sputtering and compared to RF deposited films using optimized conditions. These high mobility ITiO films have shown to extend the transmission in the NIR region compared to typical TCOs, such as ITO, exhibiting their potential in a tandem or multiple junction solar cell application. ITiO films deposited by PDC magnetron sputtering offer an increased deposition rate without a significant reduction in mobility when compared to RF sputtering, thus potentially offering PDC as a preferred industrial choice over RF sputtering. Structural characterization of the ITiO films prepared by PDC show a change in crystalline orientation and crystallite shape when compared to RF films, measured by XRD and SEM, which have been linked with the electrical parameters of the TCO

The Heavy Element Enrichment of Lyman alpha Clouds in the Virgo Supercluster

Using high S/N STIS echelle spectra (FWHM=7 km/s) of 3C 273, we constrain the metallicities of two Lya clouds in the vicinity of the Virgo cluster. We detect C II, Si II, and Si III absorption lines in the Lya absorber at z = 0.00530. Previous observations with FUSE have revealed Ly beta - Ly theta lines at this redshift, thereby accurately constraining N(H I). We model the ionization of the gas and derive [C/H] = -1.2^{+0.3}_{-0.2}, [Si/C] = 0.2+/-0.1, and log n_{H} = -2.8+/-0.3. The model implies a small absorber thickness, ~70 pc, and thermal pressure p/k ~ 40 cm^{-3} K. It is most likely that the absorber is pressure confined by an external medium because gravitational confinement would require a very high ratio of dark matter to baryonic matter. Based on Milky Way sight lines in which carbon and silicon abundances have been reliably measured in the same interstellar cloud (including new measurements presented herein), we argue that the overabundance of Si relative to C is not due to dust depletion. Instead, this probably indicates that the gas has been predominately enriched by Type II supernovae. Such enrichment is most plausibly provided by an unbound galactic wind, given the absence of galaxies within a projected distance of 100 kpc and the presence of galaxies capable of driving a wind at larger distances. We also constrain the metallicity and physical conditions of the Virgo absorber at z = 0.00337 based on detections of O VI and H I and an upper limit on C IV. If this absorber is collisionally ionized, the O VI/C IV limit requires T > 10^{5.3} K. For either collisional ionization or photoionization, we find that [O/H] > -2.0 at z = 0.00337.Comment: Final Ap.J. versio

Generation of highly ionized cadmium plasma columns for a discharge-pumped Nickel-like Cd laser

Includes bibliographical references (page 574).We report the observation of strong line emission from Ni-like Cd ions in a capillary discharge plasma. Spectroscopically pure Cd vapor was produced in a room temperature environment utilizing a capacitive discharge. The metal vapor was injected into a capillary channel where it was subsequently excited with fast current pulses of up to 200 kA These results open the possibility of observing laser amplification in the 3d94d-394p line of Ni-like Cd at 13.2 nm and in laser lines of other Nickel-like ions in a discharge-created plasma

The D/H Ratio in Interstellar Gas Towards G191-B2B

We reinvestigate the question of spatial variation of the local D/H abundance, using both archival GHRS spectra, and new echelle spectra of G191-B2B obtained with the Space Telescope Imaging Spectrograph (STIS) aboard HST. Our analysis uses stratified line-blanketed non-LTE model atmosphere calculations to determine the shape of the intrinsic WD Lyman-alpha profile and estimate the WD photospheric contamination of the interstellar lines. Although three velocity components were reported previously towards G191-B2B, we detect only two velocity components. The first component is at V(hel) ~ 8.6 km/s and the second at V(hel) ~ 19.3 km/s, which we identify with the Local Interstellar Cloud (LIC). From the STIS data we derive D/H = 1.60(+0.39,-0.27)X10^-5 for the LIC component, and D/H > 1.26X10^-5 for the 8.6 km/s component (uncertainties denote 2-sigma or 95% confidence limits). The STIS data provide no evidence for local or component-to-component variation in the D/H ratio. Despite using two velocity components for the profile fitting and using a more physically realistic WD Lyman-alpha profile for G191-B2B, our re-analysis of the GHRS data indicates a component-to-component variation as well as a variation of the D/H ratio in the LISM, neither of which are supported by the newer STIS data. We believe the most probable cause for this difference is the characterization of the background due to scattered light in the GHRS and STIS spectrographs. The two-dimensional MAMA detectors of STIS measure both the spatial and wavelength dependences of scattered light, allowing more accurate scattered light corrections than was possible with GHRS.Comment: Accepted for publication in Astrophysical Journal Letters. 10 pages + 3 figures. (Abstract is abridged.

Coherent control of enrichment and conversion of molecular spin isomers

A theoretical model of nuclear spin conversion in molecules controlled by an external electromagnetic radiation resonant to rotational transition has been developed. It has been shown that one can produce an enrichment of spin isomers and influence their conversion rates in two ways, through coherences and through level population change induced by radiation. Influence of conversion is ranged from significant speed up to almost complete inhibition of the process by proper choice of frequency and intensity of the external field.Comment: REVTEX, 13 pages + 6 eps figure

Spontaneous symmetry breaking in strong-coupling lattice QCD at high density

We determine the patterns of spontaneous symmetry breaking in strong-coupling lattice QCD in a fixed background baryon density. We employ a next-nearest-neighbor fermion formulation that possesses the SU(N_f)xSU(N_f) chiral symmetry of the continuum theory. We find that the global symmetry of the ground state varies with N_f and with the background baryon density. In all cases the condensate breaks the discrete rotational symmetry of the lattice as well as part of the chiral symmetry group.Comment: 10 pages, RevTeX 4; added discussion of accidental degeneracy of vacuum after Eq. (35

Identifying Key Factors Associated with Aggression on Acute Inpatient Psychiatric Wards

Aggressive behaviour is a critical issue for modern acute psychiatric services, not just because of the adverse impact it has on patients and staff, but also because it puts a financial strain on service providers. The aim of this study was to assess the relationship of patient violence to other variables: patient characteristics, features of the service and physical environment, patient routines, staff factors, the use of containment methods, and other patient behaviours. A multivariate cross sectional design was utilised. Data were collected for a six month period on 136 acute psychiatric wards in 26 NHS Trusts in England. Multilevel modelling was conducted to ascertain those factors most strongly associated with verbal aggression, aggression toward objects, and physical aggression against others. High levels of aggression were associated with a high proportion of patients formally detained under mental health legislation, high patient turnover, alcohol use by patients, ward doors being locked, and higher staffing numbers (especially qualified nurses). The findings suggest that the imposition of restrictions on patients exacerbates the problem of violence, and that alcohol management strategies may be a productive intervention. Insufficient evidence is available to draw conclusions about the nature of the link between staffing numbers and violence

UV Absorption Lines from High-Velocity Gas in the Vela Supernova Remnant: New insights from STIS Echelle Observations of HD72089

The star HD72089 is located behind the Vela supernova remnant and shows a complex array of high and low velocity interstellar absorption features arising from shocked clouds. A spectrum of this star was recorded over the wavelength range 1196.4 to 1397.2 Angstroms at a resolving power lambda/Delta lambda = 110,000 and signal-to-noise ratio of 32 by STIS on the Hubble Space Telescope. We have identified 7 narrow components of C I and have measured their relative populations in excited fine-structure levels. Broader features at heliocentric velocities ranging from -70 to +130 km/s are seen in C II, N I, O I, Si II, S II and Ni II. In the high-velocity components, the unusually low abundances of N I and O I, relative to S II and Si II, suggest that these elements may be preferentially ionized to higher stages by radiation from hot gas immediately behind the shock fronts.Comment: 11 pages, 2 figures, Latex. Submitted for the special HST ERO issue of the Astrophysical Journal Letter